Research is one of the most important aspects of any city-state. A well orchestrated research will give you access to more options, it will cut down some costs (when it comes to 
casting spells or 
spreading propaganda) and it will enable your city state's overall development.
All research-related information can be found under the 
Research Adviser.
Some of the principles governing research are:
- All research is possible thanks to the Research Lab. You can improve the research rate by ...researching a better rate or by using effects (civics, spells, propaganda).
- Players can only research one item at a time.
- When there's already an item being researched, a new item can still be selected to take its place. The newly selected item will become the current research.
- No research is being lost. If a new item is selected for research before current research is completed, the progress doesn't get lost. Next time you select that item for research, it will start off from where it was left.
- No automatic research. Once you've completely researched one item, research will stop unless a new item gets chosen.